add basic subclassing functionality for treeview

src/subclass/mod.rs

@@ -23,6 +23,7 @@ pub mod fixed;
 pub mod header_bar;
 pub mod icon_view;
 pub mod stack;
+pub mod tree_view;
 pub mod widget;
 pub mod window;
 
@@ -48,6 +49,7 @@ pub mod prelude {
     pub use super::header_bar::HeaderBarImpl;
     pub use super::icon_view::{IconViewImpl, IconViewImplExt};
     pub use super::stack::StackImpl;
+    pub use super::tree_view::TreeViewImpl;
     pub use super::widget::{WidgetImpl, WidgetImplExt};
     pub use super::window::{WindowImpl, WindowImplExt};
     pub use gio::subclass::prelude::*;

src/subclass/tree_view.rs

@@ -0,0 +1,13 @@
+use glib::subclass::prelude::*;
+
+use super::container::ContainerImpl;
+use ContainerClass;
+use TreeViewClass;
+
+pub trait TreeViewImpl: ContainerImpl + 'static {}
+
+unsafe impl<T: ObjectSubclass + ContainerImpl> IsSubclassable<T> for TreeViewClass {
+    fn override_vfuncs(&mut self) {
+        <ContainerClass as IsSubclassable<T>>::override_vfuncs(self);
+    }
+}